Question

If the upper and lower control limits of a process are set at plus or minus three sigma, then what percent of the units produced are expected to satisfy the customer’s requirements?
a. 68%
b. 95%
c. 99.73%

Answer 1

Answer:

c. 99.73%

Explanation:

Statistical Empirical Rule states the percentage of values that lie within a band around the mean in a normal distribution.

The rule also called as 68 - 95 - 99.7 rule depicts the proportion of under mentioned data covered within following range of standard deviation from mean:

• Mean + standard deviation = 68.27% data of the normal distribution
• Mean + (2 x standard deviation) = 95% data of the normal distribution
• Mean + (3 x standard deviation) = 99.73% data of the normal distribution